1 files changed, 41 insertions, 16 deletions

diff --git a/drivers/net/usb/cdc_mbim.c b/drivers/net/usb/cdc_mbim.c
index c9f3281506af..2e025ddcef21 100644
--- a/drivers/net/usb/cdc_mbim.c
+++ b/drivers/net/usb/cdc_mbim.c
@@ -120,6 +120,16 @@ static void cdc_mbim_unbind(struct usbnet *dev, struct usb_interface *intf)
         cdc_ncm_unbind(dev, intf);
 }
 
+/* verify that the ethernet protocol is IPv4 or IPv6 */
+static bool is_ip_proto(__be16 proto)
+{
+        switch (proto) {
+        case htons(ETH_P_IP):
+        case htons(ETH_P_IPV6):
+                return true;
+        }
+        return false;
+}
 
 static struct sk_buff *cdc_mbim_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags)
 {
@@ -128,6 +138,7 @@ static struct sk_buff *cdc_mbim_tx_fixup(struct usbnet *dev, struct sk_buff *skb
         struct cdc_ncm_ctx *ctx = info->ctx;
         __le32 sign = cpu_to_le32(USB_CDC_MBIM_NDP16_IPS_SIGN);
         u16 tci = 0;
+        bool is_ip;
         u8 *c;
 
         if (!ctx)
@@ -137,25 +148,32 @@ static struct sk_buff *cdc_mbim_tx_fixup(struct usbnet *dev, struct sk_buff *skb
                 if (skb->len <= ETH_HLEN)
                         goto error;
 
+                /* Some applications using e.g. packet sockets will
+                 * bypass the VLAN acceleration and create tagged
+                 * ethernet frames directly.  We primarily look for
+                 * the accelerated out-of-band tag, but fall back if
+                 * required
+                 */
+                skb_reset_mac_header(skb);
+                if (vlan_get_tag(skb, &tci) < 0 && skb->len > VLAN_ETH_HLEN &&
+                    __vlan_get_tag(skb, &tci) == 0) {
+                        is_ip = is_ip_proto(vlan_eth_hdr(skb)->h_vlan_encapsulated_proto);
+                        skb_pull(skb, VLAN_ETH_HLEN);
+                } else {
+                        is_ip = is_ip_proto(eth_hdr(skb)->h_proto);
+                        skb_pull(skb, ETH_HLEN);
+                }
+
                 /* mapping VLANs to MBIM sessions:
                  *   no tag     => IPS session <0>
                  *   1 - 255    => IPS session <vlanid>
                  *   256 - 511  => DSS session <vlanid - 256>
                  *   512 - 4095 => unsupported, drop
                  */
-                vlan_get_tag(skb, &tci);
-
                 switch (tci & 0x0f00) {
                 case 0x0000: /* VLAN ID 0 - 255 */
-                        /* verify that datagram is IPv4 or IPv6 */
-                        skb_reset_mac_header(skb);
-                        switch (eth_hdr(skb)->h_proto) {
-                        case htons(ETH_P_IP):
-                        case htons(ETH_P_IPV6):
-                                break;
-                        default:
+                        if (!is_ip)
                                 goto error;
-                        }
                         c = (u8 *)&sign;
                         c[3] = tci;
                         break;
@@ -169,7 +187,6 @@ static struct sk_buff *cdc_mbim_tx_fixup(struct usbnet *dev, struct sk_buff *skb
                                   "unsupported tci=0x%04x\n", tci);
                         goto error;
                 }
-                skb_pull(skb, ETH_HLEN);
         }
 
         spin_lock_bh(&ctx->mtx);
@@ -204,17 +221,23 @@ static void do_neigh_solicit(struct usbnet *dev, u8 *buf, u16 tci)
                 return;
 
         /* need to send the NA on the VLAN dev, if any */
-        if (tci)
+        rcu_read_lock();
+        if (tci) {
                 netdev = __vlan_find_dev_deep(dev->net, htons(ETH_P_8021Q),
                                               tci);
-        else
+                if (!netdev) {
+                        rcu_read_unlock();
+                        return;
+                }
+        } else {
                 netdev = dev->net;
-        if (!netdev)
-                return;
+        }
+        dev_hold(netdev);
+        rcu_read_unlock();
 
         in6_dev = in6_dev_get(netdev);
         if (!in6_dev)
-                return;
+                goto out;
         is_router = !!in6_dev->cnf.forwarding;
         in6_dev_put(in6_dev);
 
@@ -224,6 +247,8 @@ static void do_neigh_solicit(struct usbnet *dev, u8 *buf, u16 tci)
                                  true /* solicited */,
                                  false /* override */,
                                  true /* inc_opt */);
+out:
+        dev_put(netdev);
 }
 
 static bool is_neigh_solicit(u8 *buf, size_t len)